Vulnerability · Published Aug 25, 2026 · Assigned by TYPO3
CVE-2026-77136Server-Side Template Injection in extension "powermail" (powermail)
Critical 9.5
In plain English
A critical-severity security flaw in Extension "powermail" from TYPO3. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.0% (higher than 62% of all known vulnerabilities).
Official description
The extension passes the raw value of a form field configured as "This field contains the name of the sender" directly into a Fluid View as template source, without any sanitization, and renders it. An anonymous, unauthenticated user can submit Fluid template syntax in that field to execute arbitrary Fluid ViewHelpers leading to disclosure of server configuration, environment variables and application source, and potentially remote code execution. Exploitation requires only that a form field is configured as the sender_name field, a common and default-adjacent Powermail configuration. No authentication or user interaction beyond a normal form submission is required. This vulnerability is reported to be actively exploited in the wild.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| TYPO3 | Extension "powermail" | 13.0.0 – before 13.2.111.0.0 – before 12.6.10 – before 10.9.3 |
Weakness: CWE-1336 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
References
- https://typo3.org/security/advisory/typo3-ext-sa-2026-022 vendor-advisory